Canon Rebel T2i Digital Camera Review$899.99
In addition to the standard aperture-priority, shutter-priority, and manual modes, The Rebel T2i includes A-Dep (auto depth of field), Creative Auto, and full auto modes.
The Rebel T2i has the same nine-point autofocus system as most Canon DSLRs. Eight points are arranged in a rhombus, with one central point in the middle. You can either focus manually, allow the camera to focus automatically with all nine focal points, or select one of the nine specific points to use for autofocus.
The focus generally feels fast, though it slows down a bit in low light. Even in low light, however, we found that the T2i autofocus system is responsive and accurate. The focusing motor isn't too loud, but when you're recording video, its proximity to the microphone definitely provides an audible grinding noise in the background. This is a problem with most SLRs. You can read more about it in the Audio section of the Video Features portion of the review.
There is an 'autofocus assist beam,' though it's associated with the built-in flash, which will fire a short series of bursts in order to help the T2i autofocus in low light. There is no dedicated infrared focus assist beam. If you prefer to use only IR focus assist, you can purchase an external flash with this feature and set the camera to activate focus assist only when the infrared beam is available.
The T2i has three choices for focus modes: One Shot, AI Servo (AKA Continuous), and AI Focus, which switches between the two other focus modes, depending on whether the subject is in motion or not.
The Rebel T2i shoots photos exclusively in a 3:2 aspect ratio. There are three JPEG sizes available (see chart below), each size available in Fine or Normal quality. There is also the option to shoot RAW files — either alone or paired with an 18M fine quality JPEG.